A variety of devices have long been utilized to treat and dispense purified water. Such devices typically include a variety of filters, adsorption mediums and reverse osmosis membranes to remove organic and inorganic substances. Some also include ultraviolet light sources which are used to irradiate the treated water as another means of removing microorganisms that would contaminate the water. As purified water has become more widely used new apparatus and methods have been developed to purify and dispense it to a broader range of locations. One particular type of system allows municipal or approved potable well water to be purified and dispensed to grocery store customers and the like who fill a container at a stationary dispensing unit located on or about the store premises.
In such remote and generally unattended distribution of purified water a variety of unique problems and needs often arise. Such systems typically are unattended for relatively long periods of time. Maintenance may be provided by trained personnel only infrequently, perhaps monthly. Thus, problems with such systems which may arise should be as "self correcting" as possible to prevent long period or transient shut downs between maintenance calls.
One such situation arises when the standard ultraviolet decontaminating light is monitored by a sensor that may sense an ultraviolet light transient output caused by a surge of cold water producing a "below minimum intensity" reading to the sensor. In such systems the sensor would momentarily and unnecessarily shut down the pumping apparatus during this transient event when there is heat sinking of the bulb output. Such momentary shut downs could result in added wear and tear to the processing unit components and an inconvenience to the customer.
Any dispensing location subjects the dispenser to a large variety of environments, many of which may contain airborne contaminants. In addition, self service dispensers are prone to spout contamination from handling by the customers. In some current systems, an ultraviolet light is provided at the spout to help prevent contamination of the spout and purified water which contacts it. Existing spout assemblies containing ultraviolet lights have proven inadequate because the contaminants are not eradicated by the relatively short light. Further, the light and spout have been found to be inadequately enclosed, making the light more difficult to replace and generally providing an inadequate enclosure around the spout area.